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Chapter 8
Rock Record Vocab
Question | Answer |
---|---|
Describe James Hutton’s principle of uniformitarianism. | the principle that geologic processes that occurred in the past are similar to the processes that occur today |
Compare relative age and absolute age. | Relative age is the age of an object in relation to other objects and absolute age is the numeric age of an object |
Describe the law of superposition. | upper sedimentary rock layers are younger than the rock layers below them |
If an igneous intrusion is observed crossing through a layer of older sedimentary rock, what geological law applies? | law of crosscutting relationships |
When using radiometric dating to determine the absolute age of rocks, what do scientists compare? | parent isotopes are compared to daughter isotopes |
Radioactive decay is used to determine the absolute age of rocks because it happens at what rate? | at a relatively constant rate |
What is an index fossil? | a fossil used to date rock layers |
How old is the earth estimated to be? | 4.6 or 4.8 billion years old |
Layers of rock are called | strata |
What does relative age indicate? | that one rock layer is older than another layer |
A fault or body of rock is younger than any other body of rock it cuts through according to the law of | cross cutting relationships |